In general, electric vehicles, as environmentally-friendly vehicles, require less driving costs, but have problems such as short running distances, long battery charge times, and insufficient battery charge stations, compared with general internal combustion engine vehicles.
Particularly, distance to empty (DTE) of an electric vehicle is a big concern.
Therefore, in order to increase a running distance of an electric vehicle, vehicle manufacturers have been developed a technology that provides minimum energy route guide using a navigation system.
A navigation system, which is applied to an existing internal combustion engine vehicle, can provide a shortest time route from a departure point to a destination. On the other hand, a navigation system applied to an electric vehicle provides a minimum energy route in view of a characteristic thereof. That is, the navigation system used for the electric vehicle is different from the navigation system of the conventional internal combustion engine vehicle.
The electric vehicle generally has very high efficiency, compared with the existing internal combustion engine vehicle. That is, the existing internal combustion engine vehicle has a highest efficiency driving speed of about 60-80 km/h, however, the electric vehicle has a considerably low efficiency driving speed of about 30 km/h.
Therefore, when the navigation system guides with a minimum energy route of the electric vehicle, a time difference of about one and half times to two times occurs, compared with a generally-used shortest time route. Such a time difference may be disregarded for energy saving in short distance driving, however, in long distance driving, there is a problem that a consumption time may represent several hour difference.
In more detail, one of major reasons that a user who drives the electric vehicle selects a minimum energy route instead of a general shortest time route is range anxiety.
When the user searches for a destination route, if a distance to empty (DTE) is smaller than a distance of a shortest time route, it is impossible to run to the destination, and thus, a minimum energy route having small energy consumption may be selected. In this way, when the user runs with a minimum energy route, there is a merit that a time can be reduced, compared with when the user separates from a route and charges due to charge energy shortage.
However, when a distance between a departure point and a destination is a long distance, for example, about 100 km or more, due to high efficiency in a low speed of the electric vehicle, there is a problem that a minimum energy route has a difference of 1 hour or more, compared with a shortest time route. In such long distance driving, when a user charges the electric vehicle for about 1 hour at a quick charge station while route running, the user may feel comfortable.
Therefore, a method of providing more efficient route guide in consideration of a driving distance, minimum energy, and a shortest time from a departure point to a destination of the electric vehicle is requested.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention, and therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art,